Like cadmium and copper, aluminum (aluminium) is classified as a metalloestrogen, a metal with estrogenic properties. As such, aluminum has long been suspected of contributing to breast cancer risk. Aluminum has been shown to increase estrogen-related gene expression in breast cancer cells and to induce DNA damage in normal breast cells. Aluminium accumulation in breast tissue increases inflammation, which could also contribute to breast cancer risk. One study reported that the average level of aluminium in nipple aspirate fluids collected from breast cancer patients was more than twice that of similar healthy women. Now a new study has reported exposure to aluminum increases the migratory and invasive properties of hormone receptor positive (ER+/PR+) breast cancer cells, suggesting that aluminium in breast tissue could promote metastasis.

Sources of aluminum exposure

Antiperspirant and deodorant use has been posited to play a role in breast cancer through its aluminum content, although this connection is far from proven. Many antiperspirants and deodorants currently sold in the U.S. do not contain aluminum. Other common sources of exposure include antacids containing aluminium compounds and baking powder, as well as the use of aluminum cookware, utensils, packaging and containers. Consumption of acidic foods or liquids with aluminium significantly increases aluminium absorption.

Latest research finds aluminum promotes breast cancer cell mobility

The study referenced at the beginning of this news story was designed to evaluate the effects of exposure to aluminium on the migratory and invasive properties of ER+/PR+ MCF-7 human breast cancer cells. Long-term (defined as 32 weeks) but not short-term (1 week) exposure of MCF-7 cells to aluminium chloride or aluminium chlorohydrate was found to enhance the motility of the cells. Live cell imaging demonstrated that the cumulative length moved by individual aluminum-exposed breast cancer cells exceeded that of unexposed cells.

Long-term (37 week) exposure to aluminium chloride or aluminium chlorohydrate also was shown to enhance the ability of the breast cancer cells to invade through a matrigel layer (a gelatinous protein mixture used as a type of reconstituted cell membrane). The authors conclude that while the molecular mechanisms remain to be explained, the ability of aluminium salts to increase migratory and invasive properties of MCF-7 breast cancer cells suggests that aluminium in breast tissue could influence metastatic processes.